(→‎Configure the root filesystem: Added explanation on how to have seperate datasets for system directories because this was not very clear. ZFS datasets need mountpoint=legacy to be mounted through /etc/fstab)

Installing archzfs

Using the archzfs repository is highly recommended for effortless updates.

Warning: The ZFS packages are tied to the kernel version they were built against. This means it will not be possible to perform kernel updates until new packages (or package sources) are released by the ZFS package maintainer.

Format the destination disk

Format the boot partition as well as any other system partitions. Do not do anything to the Solaris partition nor to the BIOS boot partition. ZFS will manage the first, and your bootloader the second.

Setup the ZFS filesystem

First, make sure the ZFS modules are loaded,

# modprobe zfs

Create the root zpool

# zpool create zroot /dev/disk/by-id/id-to-partition

Warning: Always use id names when working with ZFS, otherwise import errors will occur.

Create necessary filesystems

If so desired, sub-filesystem mount points such as /home and /root can be created with the following commands:

# zfs create zroot/home
# zfs create zroot/root

Note that if you want to use other datasets for system directories (/var or /etc included) your system will not boot unless they are listed in /etc/fstab! We will address that at the appropriate time in this tutorial.

Swap partition

ZFS does not allow the use swapfiles, but it is possible to use a ZFS volume as swap partition. It is important to set the ZVOL block size to match the system page size; for x86_64 systems that is 4k.

Create a 8 GB (or whatever is required) ZFS volume:

# zfs create -V 8G -b 4K pool/swap

Initialize and enable the volume as a swap partition:

# mkswap /dev/zvol/pool/swap
# swapon /dev/zvol/pool/swap

After using pacstrap to install the base system, edit /root/etc/fstab to ensure the swap partition is mounted at boot:

/dev/zvol/pool/swap none swap defaults 0 0

Make sure to unmount all ZFS filesystems before rebooting the machine, otherwise any ZFS pools will refuse to be imported:

Set the bootfs property on the descendant root filesystem so the boot loader knows where to find the operating system.

# zpool set bootfs=zroot zroot

Export the pool,

# zpool export zroot

Warning: Don't skip this, otherwise you will be required to use -f when importing your pools. This unloads the imported pool.

Note: This might fail if you added a swap partition above. Need to turn it off with the swapoff command.

Finally, re-import the pool,

# zpool import -d /dev/disk/by-id -R /mnt zroot

Note: -d is not the actual device id, but the /dev/by-id directory containing the symbolic links.

If there is an error in this step, you can export the pool to redo the command. The ZFS filesystem is now ready to use.

Be sure to bring the zpool.cache file into your new system. This is required later for the ZFS daemon to start.

# cp /etc/zfs/zpool.cache /mnt/etc/zfs/zpool.cache

Install and configure Arch Linux

Follow the following steps using the Beginners' Guide. It will be noted where special consideration must be taken for ZFSonLinux.

First mount any boot or system partitions using the mount command.

Install the base system.

The procedure described in Beginners' Guide#Generate an fstab is usually overkill for ZFS. ZFS usually auto mounts its own partitions, so we do not need ZFS partitions in fstab file, unless the user made datasets of system directories. To generate the fstab for filesystems, use:

# genfstab -U -p /mnt | grep boot >> /mnt/etc/fstab

Edit the /etc/fstab:

Note:

If you chose to create datasets for system directories, keep them in this fstab! Comment out the lines for the '/, /root, and /home mountpoints, rather than deleting them. You may need those UUIDs later if something goes wrong.

Anyone who just stuck with the guide's directions can delete everything except for the swap file and the boot/EFI partition. It seems convention to replace the swap's uuid with /dev/zvol/zroot/swap.

When creating the initial ramdisk, first edit /etc/mkinitcpio.conf and add zfs before filesystems. Also, move keyboard hook before zfs so you can type in console if something goes wrong. You may also remove fsck (if you are not using Ext3 or Ext4). Your HOOKS line should look something like this:

HOOKS="base udev autodetect modconf block keyboard zfs filesystems"

Regenerate the initramfs with the command:

# mkinitcpio -p linux

Install and configure the bootloader

For BIOS motherboards

Follow GRUB#BIOS_systems_2 to install GRUB onto your disk. grub-mkconfig does not properly detect the ZFS filesystem, so it is necessary to edit grub.cfg manually:

For UEFI motherboards

Use EFISTUB and rEFInd for the UEFI boot loader. See Beginners' Guide#For UEFI motherboards. The kernel parameters in refind_linux.conf for ZFS should include zfs=bootfs or zfs=zroot so the system can boot from ZFS. The root and rootfstype parameters are not needed.

Unmount and restart

We're almost done!

# exit
# umount /mnt/boot
# zfs umount -a
# zpool export zroot

Now reboot.

Warning: If you do not properly export the zpool, the pool will refuse to import in the ramdisk environment and you will be stuck at the busybox terminal.

After the first boot

If everything went fine up to this point, your system will boot. Once.
For your system to be able to reboot without issues, you need to enable the zfs service and set the hostid.

When running ZFS on root, the machine's hostid will not be available at the time of mounting the root filesystem. There are two solutions to this. You can either place your spl hostid in the kernel parameters in your boot loader. For example, adding spl.spl_hostid=0x00bab10c.

The other solution is to make sure that there is a hostid in /etc/hostid, and then regenerate the initramfs image. Which will copy the hostid into the initramfs image.